1. Field of the Invention
The present invention relates to telecommunication systems. In particular, the invention is directed to a method, system and WAP Charging Gateway for implementing transaction-based billing for WAP services.
2. Description of the Related Art
Usage of the wireless application protocol (WAP) is becoming increasingly common in the implementing of applications and services that require a communication connection between portable terminal devices, such as mobile stations, and Internet applications and content such for example as electronic mail, the World Wide Web (WWW) and newsgroups. The wireless application protocol provides an architecture that adapts mobile phones, browser programs of mobile phones, and the WWW to work together as a functional entity. The HTML (HyperText Mark-up Language) used in the WWW is translated, when information is being transmitted to mobile stations, into a standardized Wireless Mark-up Language (WML) that has been developed for the wireless environment. Although at present the WML language is typically employed as the descriptive language of the WAP standard, it should be understood that any other description language consistent with current or future WAP standards may alternatively be used. In any event, the wireless application protocol comprises five layers: the wireless application environment (WAE), the wireless session layer (WSL), the wireless. transaction layer (WTP), the wireless transport layer security (WTLS), and the wireless datagram layer (WDP). As used herein, the wireless application environment is intended to denote, by way of example, a Wireless Telephone Application (WTA) or other suitable environment. Below the five layers of the wireless application protocol is a system dependant layer that defines the transfer mode of the information within the system in question. The currently accepted specification is WAP specification 1.1; this and other WAP-related specifications can be viewed at the WWW site associated with “wapforum.com”.
The undeniable advantage of a mobile communication network, as for example a GSM (Global System for Mobile communications) system, as compared with a public switched telephone network (PSTN) is mobility management. The mobile communication network allows a subscribing user to make and receive phone calls anywhere within the coverage area of the network. In this application, the mobile communication network is defined, by way of preferred but nonetheless illustrative example, as a digital mobile network.
In 1997, the companies Ericsson, Motorola, Nokia and Phone.com founded the WAP Forum which is an open association of terminal manufactures, operators and different service providers that anyone can join. One specific objective of the WAP architecture is to enable the use of services provided via the Internet on portable terminals whose data processing capabilities, size of display and/or storage capacity is relatively small or restricted. Such terminals may for example take the form of mobile stations and PDAs (Personal Digital Assistants). The WAP specification does not require that the air or wireless interface be implemented in any particular manner, thus permitting different operators to take advantage of a wide variety of possibilities that the standard accommodates.
At present, use of the WAP protocol in mobile stations may be effected, for example, by means of SMS (Short Message Service) short messages or via a separate switched data connection in which a connection is established by the mobile station with a specific accessible number that offers data services.
The billing of WAP services is currently implemented by invoicing the client based on the actual connection time used by the switched data connection. If the transmission of WAP protocol messages is effected using short messages, then one SMS-based WAP transaction may by way of illustration require five MO (Mobile Originated) oriented and fifteen MT (Mobile Terminated) oriented short messages.
The problem with connection time-based billing is the increased difficulty of distributing the resulting income—i.e. the fair or equitable or appropriate distribution of billed income between the service provider and the content provider. In connection time billing, all of the available services are provided to a user at the same cost. Connection time-based income therefore cannot be equitably divided between the service provider and content providers. A similar problem occurs with SMS-based WAP services; the number of messages used in providing a WAP-based service is typically unrelated to the value of the content or the quality of the particular service.